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The National Institute of General Medical Sciences (NIGMS),
one of the National Institutes of Health, supports all research
featured in this digest. Although only the lead scientists
are named, coworkers and other collaborators also contributed
to the findings. To read additional news items, visit NIGMS
News.

Cool Image: Worms and Human Infertility

This montage of tiny, transparent C. elegans—or
roundworms—may offer insight into understanding human
infertility. Researchers used fluorescent dyes to label
the worm cells and watch the process of sex-cell division,
called meiosis, unfold as nuclei (blue) move through the
tube-like gonads. Such visualization helps the scientists
identify mechanisms that enable these roundworms to reproduce
successfully. Because meiosis is similar in all sexually
reproducing organisms, what the scientists learn could apply
to humans. Courtesy of Abby Dernburg, a cell biologist at
the Lawrence Berkeley National Laboratory.

Marine Chemical Warfare Could Yield New Antibiotics

The world's vast oceans are a treasure trove for medical
researchers because many marine animals produce powerful poisons
in their daily fight for survival. These chemicals could also
work against microbes that infect humans. In their study of
the toxins produced by sea slugs, biologists Phang C. Tai
and Charles Derby at Georgia State University discovered new
clues about the chemistry of this process that may lead to
the development of new antibiotics. They discovered that these
sea creatures produce and store two harmless chemicals in
separate sacs inside their bodies. When squirted together,
the molecules combine to make a protective fluid that may
also guard the slugs against infection. The researchers are
now investigating the substance’s potential antimicrobial
properties.

Dramatic Structural Changes Reveal How Viruses
Infect Cells

Caption: Structure of
the F protein before (left) and after (right) viral
fusion. Courtesy of Theodore Jardetzky.

Like pirates commandeering a ship, viruses hijack cells.
Once inside cells, viruses use the inner machinery to reproduce
and spread infection. New research shows that certain viruses
gain entrance with the help of a large protein, called F,
studding their surfaces. Northwestern University biologists
Theodore Jardetzky and Robert Lamb detailed the structure
of the F protein, which controls the cell-fusing ability of
the viruses responsible for measles, mumps, and many human
respiratory diseases. When the virus is near a cell it can
infect, the F protein undergoes a dramatic structural change
that enables it to extend like a harpoon into the cell’s
outer membrane. The protein then collapses, pulling in the
virus and allowing it to fuse. Knowledge of the protein’s
structure before and after fusion could lead to new vaccines
and drugs for a number of viral infections.

This work was co-funded by the National Institute of Allergy
and Infectious Diseases at NIH.

Tool to Detect Potentially Dangerous Flu Strains

Caption: Superimposed
on a glycan array study (green dots) is hemagglutinin
(yellow structure, left), a viral protein necessary
for infection. The graphs (right) indicate this
protein’s binding preferences from four different
viral strains.

Many scientists believe that a pandemic flu, possibly arising
from genetic changes to a bird flu virus, is inevitable.
But now they might have an early warning system. Using a
new technology called a glycan array, researchers at the
Scripps Research Institute led by glycobiologist James Paulson
and structural biologist Ian Wilson, both members of the
NIGMS-funded Consortium for Functional Glycomics (CFG),
were able to tell how adapted a given flu strain is for
infecting human cells. For this study, they compared various
strains of bird and human flu viruses, including two from
the 1918 flu pandemic. They did not study the H5N1 strain
of bird flu. The researchers found that among the studied
strains, just two genetic changes could enable a bird flu
virus to attack human cells. The glycan array can monitor
genetic changes that allow viruses to recognize human cells
and can help detect the emergence of flu strains capable
of causing human pandemics. The technology, developed by
the CFG, is available to the entire scientific community.

NIGMS-Funded Advances Recognized as 2005’s
Most Significant

The end of each year prompts many science magazines to
highlight the most significant research advances made during
the past 12 months. We are pleased to report that NIGMS-supported
researchers made a number of the 2005 achievements featured
by Science, Chemical and Engineering News, and Science
News. Science, for example, cited discoveries made
by Institute grantees as part of its "Breakthrough of the
Year," which focused on evolution in action, and its "runners
up," which included the determination of the potassium ion
channel structure and new developments in the area of systems
biology. As in past years, this recognition underscores
the significant contributions of NIGMS-funded researchers
in advancing scientific knowledge.

Biomedical Beat is produced by the Office of Communications and Public Liaison
of the National Institute
of General Medical Sciences. Some of the research briefs
in this digest were generated from university or national
laboratory news releases. For more information about Biomedical
Beat, please contact the editor, Emily Carlson, at carlsone@nigms.nih.gov
or 301-594-1515. To talk to someone at NIGMS about this research,
call 301-496-7301. The material in this newsletter is not
copyrighted and we encourage its use or reprinting.